2026年托福阅读口语真题

2026年托福阅读口语真题Passage1TheThermohalineCirculationandGlobalClimateTheoceanisnotastagnantbodyofwaterbutadynamicenginethatconstantlyredistributesheatandnutrientsaroundtheglobe.Thismovementislargelydrivenbyaglobalconveyorbeltknownasthermohalinecirculation."Thermo"referstotemperature,and"haline"referstosalinity;differencesinthesetwophysicalpropertiescreatedensitydifferencesthatdrivethecirculation.Thisvastsystemofdeep-oceancurrentsplaysacriticalroleinregulatingEarth'sclimate,particularlyinmaintainingtherelativestabilityoftemperaturesintheNorthAtlanticregion.TheengineofthermohalinecirculationstartsintheNorthAtlanticOcean.Here,warmsurfacewaterflowsnorthfromthetropics,carriedbytheGulfStream.AsthiswaterreachesthehigherlatitudesnearGreenlandandIceland,itcools.Coldwaterisdenserthanwarmwater.Furthermore,theformationofseaiceinthesefrigidregionsincreasesthesalinityoftheremainingliquidwaterbecausesaltisexcludedfromthecrystallinestructureofice.Thiscombinationoflowtemperatureandhighsalinitymakesthewaterextremelydense,causingittosinktotheoceanfloor.Thissinkingprocess,knownasdeep-waterformation,istheprimarydrivingforcebehindtheconveyorbelt.Oncethedensewatersinks,itflowssouthwardatgreatdepths,formingtheNorthAtlanticDeepWater(NADW).ThisdeepcurrenttravelsacrosstheequatorandeventuallyintotheSouthernOcean.There,itmixeswithotherdeepwatermasses,includingcoldAntarcticBottomWater.Thecurrentsthenbranchout,circulatingintotheIndianandPacificOceans.Intheseoceanbasins,thedeepwatergraduallywarmsandupwells(risestothesurface).Theupwellingoccursbecausethewaterisdisplacedbynew,denserwatersinkingelsewhere.Onceatthesurface,thewateriswarmedbythetropicalsun,becomeslessdense,andflowsbacktowardtheNorthAtlantictocompletethecycle.Thisentireloopisestimatedtotakeupto1,000yearstocomplete.Theimplicationsofthermohalinecirculationforglobalclimateareprofound.BytransportingwarmwaterfromthetropicstotheNorthAtlantic,thesystemreleasesvastamountsofheatintotheatmosphere,warmingWesternEurope.Withoutthisheattransfer,regionsliketheUnitedKingdomandScandinaviawouldbesignificantlycooler—estimatessuggestbyasmuchas5to10degreesCelsius—placingthematlatitudinalclimatessimilartothoseofCanadaorRussia.Therefore,thestabilityofthiscirculationisparamountforthecurrentclimateconfiguration.However,scientistsareconcernedthatglobalwarmingcoulddisruptorevenshutdownthiscirculation.Astheplanetwarms,Arcticseaiceismeltingatanacceleratingrate.Thismeltwaterisfreshandlowinsalinity.WhenthisfreshwaterenterstheNorthAtlantic,itreducestheoverallsalinityanddensityofthesurfacewater.Ifthewaterbecomestoofreshandbuoyant,itmayfailtosink,effectivelyshuttingoffthe"pump"thatdrivestheconveyorbelt.Paleoclimaticevidencesuggeststhatsuchshutdownshavehappenedinthepast,oftenleadingtoabruptandseverecoolingeventsintheNorthAtlanticregion,despitetheglobaltrendbeingtowardwarming.ThisparadoxicaloutcomehighlightsthecomplexfeedbackloopswithintheEarth'sclimatesystem.Inadditiontoclimateregulation,thermohalinecirculationisvitalformarinebiology.Thedeepoceanisgenerallynutrient-poorbecauseorganicmatterfromdeadorganismssinksandisdecomposedbybacteria,consumingoxygen.However,upwellingzones,wheredeepwaterreturnstothesurface,bringthesenutrientsbackup.Thesenutrients,suchasnitratesandphosphates,fertilizethesurfacewaters,leadingtomassivephytoplanktonblooms.Thesebloomsformthebaseofthemarinefoodweb,supportingeverythingfromzooplanktontolargewhalesandcommercialfisheries.Thus,anydisruptiontothedeep-waterformationandupwellingprocessescouldhavecatastrophicconsequencesforglobalmarineecosystemsandhumanfoodsecurity.Questions1-101.Theword"stagnant"inthepassageisclosestinmeaningtoA.流动的B.停滞的C.深奥的D.广阔的2.Accordingtoparagraph2,whattwofactorscausethewaterintheNorthAtlantictobecomedenseenoughtosink?A.HightemperatureandlowsalinityB.LowtemperatureandhighsalinityC.HighsalinityandhighpressureD.Increasedwindspeedandlowtemperature3.Theword"excluded"inthepassageisclosestinmeaningtoA.包含B.冻结C.排除D.溶解4.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?A.Thesinkingprocessistheonlyforcethatmovestheconveyorbelt.B.Deep-waterformationisthemainmechanismthatpowerstheglobalcirculation.C.Theconveyorbeltisdrivenbythetemperatureofthesinkingwater.D.Withoutdeep-waterformation,theoceanwouldbestagnant.5.Accordingtoparagraph3,whathappenstothedeepwaterasitcirculatesthroughtheIndianandPacificOceans?A.Itbecomesdenserandsinksfurther.B.Itmixeswithsurfacewaterimmediately.C.Itgraduallywarmsandrisestothesurface.D.Itfreezesandformsseaice.6.Theword"paramount"inthepassageisclosestinmeaningtoA.次要的B.未知的C.至关重要的D.可变的7.WhydoestheauthormentiontheUnitedKingdomandScandinaviainparagraph4?A.ToillustratethepotentialtemperaturedropinEuropeifthecirculationstops.B.TocomparetheirclimatewiththatofCanada.C.Toshowthattheyarelocatedinthetropics.D.ToprovethattheGulfStreamisweakening.8.Accordingtoparagraph5,howcouldglobalwarmingleadtoacoolingeventintheNorthAtlantic?A.Byincreasingthespeedofthewinds.B.Bycausingseaicetoformfaster.C.Byaddingfreshwaterthatpreventssinking.D.Byincreasingthesalinityoftheocean.9.Theword"paradoxical"inthepassageisclosestinmeaningtoA.预期的B.矛盾的C.危险的D.渐进的10.Whatisthemainpurposeofparagraph6?A.Todescribetheformationofphytoplankton.B.Toexplaintheimportanceofupwellingformarinelife.C.Todiscussthedecompositionoforganicmatter.D.Tocriticizecommercialfishingpractices.Passage2TheOriginsofAgricultureForroughly95%ofhumanhistory,ourspeciessurvivedashunter-gatherers.Peoplelivedinsmall,mobilebands,movingfrequentlytofollowanimalherdsandgatherseasonalfruitsandvegetables.Thislifestylechangeddramaticallyaround12,000yearsagowiththeadventofagriculture,oftenreferredtoastheNeolithicRevolution.Thetransitionfromforagingtofarmingwasnotasuddeneventbutagradualprocessthatoccurredindependentlyinseveralregionsoftheworld,includingtheFertileCrescent,Mesoamerica,andChina.Understandingwhythisshiftoccurredhasbeenacentralquestioninarchaeologyandanthropologyfordecades.Thetraditionalexplanationfortheriseofagricultureisoftenframedasa"progress"model.Inthisview,agriculturewasaconsciousdiscoveryorinventionthatofferedasuperiorwayoflife.Bydomesticatingplantsandanimals,humanscouldproduceasurplusoffood,whichallowedforpopulationgrowth,theestablishmentofpermanentsettlements,andtheeventualdevelopmentofcomplexcivilizations.Underthismodel,hunter-gathererswereseenaslivingonthemarginofsurvival,constantlystrugglingagainststarvation,andagriculturewasthelogicalsolutiontoimprovetheircondition.However,archaeologicalevidencesuggeststhatthis"progress"modelisflawed.Studiesofmodernhunter-gatherersandanalysisofskeletalremainsfrompre-agriculturalpopulationsindicatethatforagersoftenhadavariedandnutritiousdiet.Theyworkedfewerhourstoobtainfoodthanearlyfarmersandgenerallydidnotsufferfromthe"diseasesofcivilization"thatlaterplaguedagriculturalsocieties.Incontrast,earlyagriculturalpopulationsexperiencedadeclineinhealth.Relianceonafewstaplecropsledtonutritionaldeficiencies,andcloseproximitytodomesticatedanimalsandlarge,densepopulationsfacilitatedthespreadofinfectiousdiseases.Furthermore,thephysicallaboroffarming—grindinggrain,clearingland,andplanting—wasoftenmorearduousthanthevariedtasksofforaging.Ifagriculturedidnotimmediatelyimprovequalityoflife,whydiditemerge?Oneprominenttheoryfocusesonpopulationpressure.AshumanpopulationsslowlygrewfollowingtheendofthelastIceAge,thecarryingcapacityoftheenvironmentforhuntingandgatheringmayhavebeenreached.Inresource-richareas,foragingremainedviable,butinregionswherewildresourcesbecamescarceorlesspredictable,humanswereforcedtodomesticateplantstoensureastablefoodsupply.Thiswasnotnecessarilyachoicebutatrap:oncepopulationdensitiesincreasedtoapointwhereforagingcouldnolongersupporteveryone,societieswerecommittedtotheintensivelaboroffarming.Climatechangealsoplayedasignificantrole.TheendofthePleistoceneepoch(around11,700yearsago)markedthebeginningoftheHolocene,aperiodcharacterizedbyawarmer,morestableclimate.Thisstabilityallowedspecificwildplants,particularlycerealslikewheatandbarley,tothriveinlargerconcentrationsintheFertileCrescent.Theabundanceofthesewildgrainsmayhaveencouragedhumanstosettleinoneareaforlongerperiodstoexploitthem.Overtime,throughaprocessofunconsciousselection,humansbegantofavorplantswithdesirabletraits,suchaslargerseedsornon-shatteringrachises(thestemsthatholdtheseeds).Eventually,theseplantsbecamesodependentonhumaninterventionforpropagationthattheywereeffectivelydomesticated.Thetransitiontoagriculturealsobroughtaboutprofoundsocialchanges.Withsurplusfoodcametheneedforstorageandmanagement.Thisledtothedevelopmentofnewtechnologies,suchaspotteryandgranaries.Italsonecessitatednewformsofsocialorganization.Landownershipbecameaconcept,andsocialhierarchiesbegantoemergebasedoncontrolofresources.Unlikehunter-gatherersocieties,whichtendedtobeegalitarian,agriculturalsocietiesoftendevelopeddistinctclassesofrulers,priests,andcraftspeople.Thus,whileagriculturemayhaveimposedaheavierphysicalburdenandpoorerhealthontheaverageindividual,itlaidthefoundationforthemodernworld,enablingtheaccumulationofwealthandtheriseofcomplexstate-levelsocieties.Questions11-2011.Theword"advent"inthepassageisclosestinmeaningtoA.结束B.到来C.拒绝D.研究12.Accordingtoparagraph2,the"progress"modelsuggeststhatagriculturewasA.adifficultandunhealthylifestyle.B.adiscoverythatimprovedhumanlife.C.forceduponhumansbyclimatechange.D.anaccidentalbyproductofhunting.13.Theword"arduous"inthepassageisclosestinmeaningtoA.繁重的B.熟练的C.短暂的D.多样的14.Whydoestheauthormentionskeletalremainsinparagraph3?A.Toprovethathunter-gathererslivedlongerthanfarmers.B.Toshowthatearlyfarmershadbetterteeth.C.Toprovideevidencethatthehealthofearlyfarmerswasworsethanforagers.D.Todemonstratethatagriculturespreadthroughmigration.15.Whichofthefollowingismentionedinparagraph4asareasonfortheshifttoagriculture?A.Thedesiretocreatecomplexcivilizations.B.Theneedtosupportagrowingpopulation.C.Theinventionofmetaltools.D.Theextinctionoflargegameanimals.16.Theword"viable"inthepassageisclosestinmeaningtoA.不可能的B.可行的C.危险的D.著名的17.Accordingtoparagraph5,howdidclimatechangecontributetotheoriginsofagriculture?A.Itcausedwildplantstobecomeextinct.B.Itmadehuntingimpossibleduetoice.C.Itcreatedstableconditionsthatallowedcerealstogrowabundantly.D.Itforcedhumanstomovetohigheraltitudes.18.Thephrase"unconsciousselection"inthepassagereferstoA.farmerschoosingseedsdeliberately.B.geneticmodificationinmodernlabs.C.naturalselectionactingonwildplants.D.humansunknowinglyfavoringplantswithcertaintraitsovergenerations.19.Accordingtoparagraph6,whatwasamajorsocialdifferencebetweenhunter-gathererandagriculturalsocieties?A.Agriculturalsocietiesweremoreegalitarian.B.Hunter-gatherershadstrictsocialhierarchies.C.Agriculturalsocietiesdevelopedsocialclassesandpropertyownership.D.Hunter-gatherersdidnothaveanyformofleadership.20.Lookatthefourletters[A,B,C,D]thatindicatewherethefollowingsentencecouldbeaddedtothepassage."Thiscreatedafeedbackloop:morefoodledtomorepeople,whichrequiredevenmorefood."Wherewouldthesentencebestfit?A.Afterthefirstsentenceinparagraph2.B.Afterthelastsentenceinparagraph2.C.Afterthelastsentenceinparagraph4.D.Afterthefirstsentenceinparagraph6.Passage3AvianIntelligence:TheCognitionofCorvidsForcenturies,humanshaveconsideredintelligencetobeadefiningcharacteristicthatseparatesusfromtherestoftheanimalkingdom.Whileprimates,particularlygreatapes,havetraditionallybeenthefocusofanimalcognitionresearch,recentstudieshaverevealedthatagroupofbirdsknownascorvids—membersofthecrowfamily,includingcrows,ravens,andjays—possesscognitiveabilitiesthatrivalthoseofchimpanzees.Despitehavingaverydifferentbrainstructure(lackingthelayeredneocortexfoundinmammals),corvidsdemonstrateremarkableskillsintooluse,socialreasoning,andfutureplanning.Oneofthemoststrikingexamplesofcorvidintelligenceistooluse.TheNewCaledoniancrow,nativetothePacificislands,manufactureshookedtoolsfromtwigsandleavestoextractinsectsfromtreebark.Thisisnotmerelyinstinctualbehavior;thesebirdsshowanunderstandingofthephysicalpropertiesoftheirtools.Incontrolledexperiments,NewCaledoniancrowshavedemonstratedtheabilitytochoosetoolsofappropriatelengthandwidthforspecifictasks.Furthermore,theycansolvemulti-steppuzzlesthatrequireusingashorttooltoretrievealongtool,whichisthenusedtogetfood.Thisabilitytouse"toolstomaketools"ortounderstandcausalrelationshipswasoncethoughttobeuniquetohumans.Socialintelligenceisanotherdomainwherecorvidsexcel.Manycorvidspeciesliveincomplexsocialgroupsthatrequiresophisticatedcommunicationandmemory.Ravens,forinstance,areabletoremembertheindividualswhohavecheatedthemorthreatenedtheminthepastandadjusttheirbehavioraccordingly.Theyalsoformalliancesandengagein"third-party"politics,wheretheyassesstherankrelationshipsbetweenotherbirds.Thissocialcognitionextendstotheirabilitytodeceive.Westernscrubjays,ifobservedwhilecaching(hiding)food,willlaterre-hidetheirstashinasecretlocationwhentheobserverisabsent,suggestingtheypossessaprimitive"theoryofmind"—theabilitytounderstandthatanotherindividualhasknowledgeandintentionsdifferentfromtheirown.Perhapsthemostimpressivecognitivefeatobservedincorvidsisthecapacityforfutureplanning,orepisodic-likecognition.Inafamousexperiment,scrubjayswerekeptintwodifferentcompartmentswithdistinctfeedingregimes:onecompartmentprovidedbreakfast,whiletheotherdidnot.Ontheeveningbefore,thebirdsweregivenaccesstofoodtocache.Thejaysconsistentlystoredmorefoodinthecompartmentwheretheyknewtheywouldbehungrythenextmorning,eveniftheywerenothungryatthetimeofcaching.Thisindicatestheycouldanticipateafutureneedandactaccordingly,atraitthatinvolvesmentaltimetravelandisrarelyseenoutsideofhumans.Theneurologicalbasisofthisintelligenceisasubjectofintensescientificinterest.Birdshaveabrainstructurecalledthepallium,which,despitelackingthesix-layeredneocortexofmammals,isdenselypackedwithneurons.Recentresearchhasshownthatthebirdpalliumcontainsfarmoreneuronspercubicmillimeterthanthemammaliancortex.Thishighneuronaldensitymaycompensateforthesmalleroverallbrainsize,allowingforcomplexinformationprocessing.Theconvergentevolutionofintelligenceinbirdsandmammalssuggeststhatadvancedcognitionisnotlimitedtoaspecificbrainanatomybutcanarisethroughdifferentneuralarchitectures.Theimplicationsofcorvidintelligenceextendbeyondmerecuriosity.Understandinghowthesebirdssolveproblemsandnavigatetheirsocialworldsprovidesinsightsintotheevolutionofthemind.Itchallengestheanthropocentricviewthatintelligenceisalinearladderwithhumansatthetop.Instead,intelligenceappearstobeacollectionofadaptivetoolsthatevolveinresponsetospecificenvironmentalpressures.Forcorvids,survivinginvariableandoftenharshenvironments,relyingonscatteredfoodsources,andnavigatingcomplexsocialhierarchieshavedriventheevolutionofabraincapableofabstractthoughtandforesight.Questions21-3021.Theword"rival"inthepassageisclosestinmeaningtoA.模仿B.竞争C.敌对D.匹敌22.Accordingtoparagraph2,whatindicatesthatNewCaledoniancrows'tooluseisnotjustinstinct?A.Theyusetoolstofindmates.B.Theyunderstandthephysicalpropertiesneededforthetask.C.Theyonlyusetoolsfoundontheground.D.Theyobservehumansusingtools.23.Theword"casual"inthepassageisclosestinmeaningtoA.偶然的B.因果的C.表面的D.正式的24.WhatdoestheauthorimplyaboutthebehaviorofWesternscrubjaysinparagraph3?A.Theyareunabletorecognizeotherbirds.B.Theyhavetheabilitytounderstandtheperspectiveofothers.C.Theyhidefoodonlywhentheyarehungry.D.Theyarethemostintelligentbirds.25.Accordingtoparagraph4,whydidthescrubjaysintheexperimentcachemorefoodinthe"no-breakfast"compartment?A.Theywerehungrierinthatcompartment.B.Theypreferredtheenvironmentofthatcompartment.C.Theyanticipatedbeinghungrytherethenextmorning.D.Theywantedtotricktheresearchers.26.Theword"convergent"inthepassageisclosestinmeaningtoA.趋同的B.分歧的C.古老的D.相似的27.Howdoestheauthorexplainthehighintelligenceofbirdsdespitetheirsmallbrainsizeinparagraph5?A.Theyhavealayeredneocortexlikemammals.B.Theirbrainstructure,thepallium,hasaveryhighdensityofneurons.C.Theirbrainsgrowlargerduringthewinter.D.Theyusealargerpercentageoftheirbrainthanhumans.28.Whichofthefollowingcanbeinferredfromparagraph6abouttheevolutionofintelligence?A.Itisalinearprocessleadingtohumans.B.Itoccursonlyinsocialanimals.C.Itisdrivenbyspecificenvironmentalchallenges.D.Itrequiresalargebrainvolume.29.Theauthormentions"chimpanzees"inthefirstparagraphinordertoA.emphasizethatprimatesarethemostintelligentanimals.B.provideastandardofcomparisonforcorvidintelligence.C.suggestthatcorvidsevolvedfromprimates.D.arguethatchimpanzeesarebetterattooluse.30.Directions:Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.CompletethesummarybyselectingtheTHREEanswerchoicesthatexpressthemostimportantideasinthepassage.Somesentencesdonotbelonginthesummarybecausetheyexpressideasthatarenotpresentedinthepassageorareminorideasinthepassage.Corvids,afamilyofbirds,displayhighlevelsofcognitiveabilitycomparabletomammals.________________________________________________________________________A.Corvidsmanufactureandusetoolswithanunderstandingofphysicalproperties.B.Mostbirdsareincapableofsolvingcomplexpuzzleswithouthumanhelp.C.Corvidsdemonstratesocialintelligenceandtheabilitytoplanforthefuture.D.Thebirdbrainhasahighneuronaldensitythatsupportscomplexprocessing.E.Corvidsarephysicallystrongerthanmostotherbirdspecies.F.Intelligenceinanimalsissolelydeterminedbythesizeofthebrain.****SpeakingSectionTask1Somepeoplebelievethatuniversitiesshouldrequirestudentstotakeclassesinmanydifferentsubjects(suchasphilosophy,art,andhistory)outsidetheirmajorfieldofstudy.Othersbelievethatstudentsshouldfocusexclusivelyontheirmajortograduatequickly.Whichviewdoyouagreewith?Usespecificreasonsandexamplestosupportyouranswer.Task2ReadingAnnouncement:UniversityLibrarytoImplement24-HourStudyRoomsTheuniversityadministrationhasannouncedthatthemainlibrarywillnowofferdesignated24-hourstudyroomsduringthefinalexamperiod.Previously,thelibraryclosedat2:00AM.Theadministrationstatesthatthischangeisinresponsetonumerousstudentcomplaintsregardinglackofspaceandinadequatestudyhoursduringhigh-stresstimes.Additionally,securityguardswillbestationedattheentranceoftheseroomstoensurestudentsafety.ListeningConversation:Man:Hey,didyouseethenewsaboutthelibrarystayingopen24hours?Woman:Yeah,Isawtheannouncement.It’sabouttime,honestly.Man:Really?Ithinkit’sabitexcessive.Imean,whoneedstostudyuntil6:00AM?Itseemslikeitwouldjustencouragebadhabits,likeprocrastination.Ifstudentsknowtheycanstayallnight,they’lljustwaituntilthelastminutetostartworking.Woman:Idon’tthinkso.MostpeopleIknowdon'twanttobetherethatlate;theyaretherebecausetheyhavetobe.Alotofstudentshaveheavycourseloadsandjobsduringtheday.Theonlytimetheyhavetofocusontheirexamsislateatnight.It’snotaboutprocrastination;it’saboutfindingablockoftimewhereyouwon'tbedisturbed.Man:IguessIhadn'tthoughtaboutthestudentswithjobs.Butstill,isn'titgoingtobeexpensivetopaysecurityguardsallnight?Woman:Maybe,buttheannouncementmentionedsafety.Ifthelibraryisopen,studentswon'thavetostudyinunsafeplacesoff-campusorwalkhomealoneinthedark.Thesafetybenefitisworththecost.Thewomanexpressesheropinionontheuniversity’splan.Reportheropinionandthereasonsshegivesforholdingthatopinion.Task3ReadingPassage:TheConceptof"Signaling"inEconomicsIneconomicsandevolutionarybiology,"signaling"referstotheideathatindividualscanconveytheirhiddenqualitiesorintentionstoothersthroughcostlyactionsthataredifficulttofake.Thecostofthesignalensuresthatonlyindividualswhogenuinelypossessthehigh-qualitytraitcanaffordtosendit.Thisresolvestheproblemof"asymmetricinformation,"whereonepartyhasmoreinformationthantheother.Forexample,acompanymightofferacomprehensivewarrantytosignalthehighqualityofitsproduct,asacompanywithlow-qualityproductscouldnotaffordthehighcostofrepairs.ListeningLecture:Professor:Okay,let'slookatanexampleofsignalingintheanimalkingdom.Considerthepeacock.Themalepeacockhasamassive,colorfultail.Now,thistailseemslikeaterriblesurvivalstrategy.It’sheavy,itmakesflyingdifficult,anditattractspredators.Sowhywouldnaturalselectionfavorsuchatrait?Well,thetailservesasasignaltopotentialmates—femalepeahens.Thetailcommunicatesthemale'sgeneticqualityandhealth.Hereisthelogic:growingandmaintainingsuchalarge,brighttailrequiresalotofenergyandresources.Onlyamalewhoisinexcellenthealthandhasastrongimmunesystemcanaffordtodivertthatmuchenergyawayfromsurvivalandintogrowingatail.Asickorweakpeacocksimplycannotproduceatailthatbigandbright;hewouldn'tsurvive.Therefore,whenafemaleseesamalewithalargetail,sheknowsheisgeneticallyfit,becausethecostofthesignalactsasaguaranteeofhisquality.It’sanhonestsignalofhisfitness.Explainhowtheexampleofthepeacockillustratestheconceptofsignaling.Task4ListeningLecture:Professor:Today,we'regoingtotalkabouttwospecificstrategiesplantsusetosurviveinenvironmentswherewaterisscarce—specifically,desertenvironments.Theseadaptationshelpthemminimizewaterlossandmaximizewateruptake.Thefirststrategyiscalled"droughtdeciduousness."Youprobablyknowthatintemperateclimates,treeslosetheirleavesinthewinterbecauseit'scold.Well,inthedesert,someplantslosetheirleavesduringthedryseason,whichisthesummer.Leavesaretheprimarysiteoftranspiration,orwaterloss.Bysheddingtheirleaveswhenwaterisunavailable,theplantdrasticallyreducestheamountofwateritlosesthroughevaporation.Theplantmightlookdeadduringthistime,butit’sjustdormant.Whentherainsfinallycome,itquicklygrowsnewleaves,flowers,andproducesseedsbeforethewaterrunsoutagain.Thesecondstrategyinvolvesmodifyingtheleafstructuretoreducewaterloss,knownas"succulence."Succulentplants,likecacti,haveevolvedleavesthataremuchdifferentfromwhatyouseeonatypicalplant.Inmanycacti,theleaveshavebeenreducedtospines.Spineshaveaverysmallsurfaceareacomparedtoflatleaves,sotheylosealmostnowater.Butwait,youmightask,iftheleavesarespines,howdoestheplantphotosynthesize?Well,thestemhastakenoverthatjob.Thestemsarethickandfleshy,allowingthemtostorelargeamountsofwaterininternaltissues,andtheycontainchlorophylltoperformphotosynthesis.Thisstructuralchangeallowstheplanttosurvivelongperiodsofdrought.****答案与解析阅读部分答案及解析1.B解析：文中提到"Theoceanisnotastagnantbodyofwater..."，意为海洋不是一潭死水（停滞的）。Stagnant对应B选项“停滞的”。2.B解析：根据第二段最后两句："Coldwaterisdenserthanwarmwater.Furthermore,theformationofseaice...increasesthesalinity..."，导致海水密度大得足以下沉的两个因素是低温和高盐度。3.C解析：文中提到"saltisexcludedfromthecrystallinestructureofice"，意为盐分被排除在冰的晶体结构之外。Excluded对应C选项“排除”。4.B解析：原句意为：“这种下沉过程，即深水形成，是驱动传送带的主要动力。”B选项“深水形成是驱动全球环流的主要机制”最准确地表达了这一核心信息。5.C解析：根据第三段："Intheseoceanbasins,thedeepwatergraduallywarmsandupwells(risestothesurface)."深水在印度洋和太平洋逐渐变暖并上升到表面。6.C解析：文中提到"thestabilityofthiscirculationisparamountforthecurrentclimateconfiguration"，意为该环流的稳定性对于当前的气候配置至关重要。Paramount对应C选项“至关重要的”。7.A解析：作者提到英国和斯堪的纳维亚是为了说明如果没有北大西洋暖流带来的热量，这些地区的温度将显著下降，从而论证该环流对欧洲气候的调节作用。8.C解析：根据第五段："WhenthisfreshwaterenterstheNorthAtlantic,itreducestheoverallsalinityanddensity...Ifthewaterbecomestoofresh...itmayfailtosink..."，全球变暖导致冰层融化，淡水注入降低了海水密度，阻止其下沉，可能导致环流停止，从而引发该地区的冷却事件。9.B解析：文中提到"Thisparadoxicaloutcome..."，指在全球变暖背景下，北大西洋地区却出现冷却事件，这是一种看似矛盾的结果。Paradoxical对应B选项“矛盾的”。10.B解析：第六段主要讨论了温盐环流带来的营养物质上涌对于海洋生物（浮游植物、食物网）的重要性。11.B解析：文中提到"Thetransitionfromforagingtofarming...around12,000yearsagowiththeadventofagriculture"，意为农业的到来。Advent对应B选项“到来”。12.B解析：根据第二段："Inthisview,agriculturewasaconsciousdi